Two recent murders in California have roiled the nation's debate over immigration. One case involves a man living in the United States illegally. He's been charged with raping and murdering a woman in her home in Santa Maria, Calif. The suspect in the other case, the murder of a San Francisco woman, was also an undocumented resident. NPR's Richard Gonzales reports that these crimes have reignited the argument over immigration enforcement.

RICHARD GONZALES, BYLINE: The details of this latest crime are difficult to hear. The victim was 64-year-old Marilyn Pharis, a civilian contractor who worked at Vandenberg Air Force Base. Her alleged assailants were 29-year-old Victor Martinez Ramirez and another man, who on the morning of July 24, broke into Pharis' home. They sexually assaulted her and beat her with a hammer. Pharis died eight days later. Martinez Ramirez is in the country illegally. He also had a long criminal record with at least four arrests dating back to 2009, and he had been released from jail just a few days before allegedly attacking Marilyn Pharis. So why was he on the street? The local police chief took aim at the Obama administration.

(SOUNDBITE OF NEWS CONFERENCE)

RALPH MARTIN: I think this is a national issue. I think it starts in Washington, D.C. with this administration that we see and their policies.

GONZALES: Santa Maria police chief Ralph Martin didn't stop there. At a news conference last week, he also blamed a voter-approved state law that reduces some drug charges to misdemeanors.

(SOUNDBITE OF NEWS CONFERENCE)

MARTIN: And I am not remiss to say that from Washington, D.C. to Sacramento, there's a blood trail into the bedroom of Marilyn Pharis.

GONZALES: In a statement, federal immigration officials say they did ask local authorities to detain Martinez Ramirez last year, when he was picked up on a felony charge. But that charge was reduced to a misdemeanor. And under state law, local authorities will hold an inmate for the feds only in the case of a serious crime. But the rhetoric and the heat are unmistakable. This case follows on the heels of the tragic murder of Kathryn Steinle, a San Francisco woman who was killed by another man who is in the country illegally. That murder gained national attention in part because Republican presidential candidate Donald Trump almost immediately pointed his finger at one example of the crimes he says are being committed by illegal immigrants.

JOHN AVALOS: We're in a moment like a Willie Horton moment right now.

GONZALES: That's San Francisco supervisor John Avalos. He says the alleged crimes of two illegal immigrants are being used to demonize all illegal immigrants. But he doesn't expect that there will be any changes in his city's policies. San Francisco is one of more than 300 jurisdictions nationwide, sometimes called sanctuary cities, that don't cooperate with detainer requests from Immigration and Customs Enforcement.

AVALOS: The ICE detainer requests that come to counties from the federal government are unconstitutional. The federal courts have determined that they're unconstitutional, and there's no way of getting around that.

GONZALES: Last year, an Oregon federal court ruled that ICE detainer requests violate the Fourth Amendment. The ruling was not appealed by the government. Mark Krikorian is the executive director of the D.C.-based Center for Immigration Studies, a group favoring immigration restrictions. He says the sanctuary cities have always been controversial, but this time, it's different.

MARK KRIKORIAN: Politically very incendiary and is almost certainly going to end up being - figuring into the presidential campaign because it's not going to go away.

GONZALES: And Krikorian adds that two high-profile murders almost ensure that this issue won't be forgotten when lawmakers return to Washington this fall. Richard Gonzales, NPR News, San Francisco. Transcript provided by NPR, Copyright NPR.